Drum clamp



@- 24 E967 A. R. TANGUAY ETAI. 3,348,288

DRUM CLAMP Filed Oct. l, 1965 5 Sheecs-ShesecI 1 INVENTORS ARMAND RTANGUAY G RTSHJMAB KURO @CL 24 w7 A. R. TANGUAY ETAI. 3,348,288

DRUM CLAMP Filed Oct. l, 1965 5 Sheets-Sheet 2 INVENTORS ARMAND R. TANGUAY QEORGE T SHIMUKURO BT? m1 l E f Q ATTORNEYS @at 24, i967 A. R. TANGUAY ETAL 3,348,288

DRUM CLAMP 5 Sheets-Sheet 3 Filed OCT.. l, 1965 sm U R om TA mr. WD D N ME AR A BEAEORG 'if SH IMABUKURO ATTRNEVS @Ch 24 l957 A. R. TANGUAY ETAL 3,348,283

DRUM CLAMP Filed Oct. 1, 1965 5 Sheets-Sheet 4 INVENTORS ARMAND R.TANGUAY 'i'. SHIMABUKURO wir ATTORNEYS Y L A T E Y A U G N A T R A.

DRUM CLAMP 5 Sheets-Sheet 5 Filed Oct. l, 1965 AR S U @Gm TNU E Nm N P` WRA., 0 N IDH A NS MT. R

Unted States Patent() DRUM CLAMP Armand' R. Tanguay, Pasadena, and George T. Shimabukuro, Monterey Park, Calif., assignors to Xerox Corporation, Rochester, N.Y., a corporation of New York Filed Det. 1, 1965, Ser. No. 492,223 3 Claims. (Cl. 29-118) ABSTRACT OF THE DISCLOSURE Apparatus for securing a sheet of flexible material to a drum including a clamp bar supported Within the drum actuatable -by means of an axially movable cam for securingfa'leadingV edge of sheet material and a wiper bar supported externally of the drum to provide a tension on the sheet as it is wrapped thereabout and to secure the trailing edge.

This application relates to improved means for clamping a sheet of flexible material to a drum.

There are many arts in which it is desired to firmly apply and easily remove a sheet of paper, plastic, thin metal or other reasonably flexible material to a drum, particularly a rotatable drum. These lields include facsimile recording, seismographic recording, spirit duplicating, lithographie printing and many others.

It is accordingly an object of the invention to provide improved means for clamping a sheet of flexible material to a drum.

It is a further object to provide an improved means for clamping a sheet of flexible material to a drum in which the material need not be prepunched or otherwise specially prepared.

It is still a further object of the invention to provide means for clamping a sheet of flexible material to a drum in which the length of the sheet of the material is not critical.

It is still a further object of the invention to provide means for clamping a sheet of flexible material to a drum which is operable -by untrained clerical personnel and which holds the sheet firmly to the surface of the drum.

The invention and its objects will be more fully explained with reference to the drawings.

FIG. 1 is an isometric view of a drum ready to receive a sheet of material;

FIG. 2 is an isometric view of a drum holding one edge of the sheet of material;

FIG. 3 is an isometric view of the drum around which a sheet of material is being wrapped;

FIG. 4 is an isometric view of the drum with a sheet of material clamped therearound;

FIG. 5 is a cross-sectional view of the apparatus of FIGS. 1 through 4; and

FIG. 6 is a longitudinal section through the apparatus of FIGS. l through 4.

Referring to FIG. 1 there is shown a drum 10, prefer-- ably but not necessarily circular in section, which is mounted on a shaft 11 which in turn is journaled in bearings 12 for rotation with respect to a frame 13. It would be equally possible to employ a fixed shaft and journal the drum for rotation about the shaft. A drive mot-or 14 rotates drum through gears 15 at a speed appropriate for the intended use of the drum, i.e., a duplicating machine drum, facsimile recorder drum, or the like. A second clock type motor 16 usable only when applying a sheet to the drum for clamping is mounted so as to drive the drum 10 at a very low speed on the order of a few ICC revolutions per minute. Motor 16 will normally include an internal clutch as is commercially available in motors of this type. A clamp bar 17 is mounted in a slot 18, these elements being more clearly shown in FIGS. 5 and 6. At least one edge of this slot is preferably inclined from a radius and bar 17 includes a corresponding lip and is shaped to conform to slot 18. By depressing a button 19 projecting axially from the visible end of drum 10, clamp `bar 17 may be raised above the surface of dr-um 10 to the position sho-wn. A further button 28 not visible in this figure, is on the opposite end of drum 10, and may be depressed to retract clamp bar 17 into slot 18 so that it lies approximately flush with the surface of drum 10.

As a first step in loading a sheet of flexible material onto the drum, one edge of the material 25 is inserted under and against clamp bar 17 which is then lowered, wedging the paper firmly between clamp bar 17 and one side of slot 1S.

FIG. 2, shows a sheet of material 25 clamped in this manner.

Drum 10 also includes a wiper bar 20 and a corresponding slot 21, positioned near slot 18. Wiper bar 20 is held at each end by spring means 22 which are attached to bearings 23 lfor rotation about shaft 11. Wiper bar 20 is shown in slot 21 in FIG. l, while in FIG- 2 wiper bar 20 has been lifted out of slot 21.

FIG. 3 illustrates what happens as drum 10 is rotated away from the viewer either manually or preferably by motor 16. Stops 24 mounted on frame 13 prevent wiper bar 20 from rotating with drum 10 when the bar is out of slot 21 as shown in FIG. 3. Bar 20 is then held against the surface of drum 10 by spring means 22 and as drum 10 slowly turns under wiper bar 20, the sheet of material 25 is drawn firmly under a windup tension against the surface of drum 10 by the smoot-h underside of the bar.

FIG. 4 shows the completion of this process. When slot 21 has rotated 'beneath clamp bar 20, the bar will be drawn into the slot, clamping thereunder the end of the sheet of material 25 opposite to that which is clamped under clamp bar 17.

As clamp bar 20 falls into slot 21, it is no longer prevented from rotating by stops 24 and the drum 10 is now entirely ready for its normal operati-on, in whic-h both clamp -bars rotate together with the drum as it is driven by motor 14. It is apparent that no hand operations are required once sheet 25 has been clamped beneath clamp bar 17. To remove sheet 25, it is only necessary to raise clamp bar 17, remove the edge of the sheet held thereunder, lift clamp bar 20 out of its slot and rest it on an uncovered portion of drum 10.

The length of sheet 25 is not extremely critical. The sheet must be long enough for one end to lie under bar 20, but the size of slot 21 will accommodate a certain excess length. A further excess will extend outside slot 21 and may be manually trimmed olf.

FIG. 5 is a cross-sectional view of drum 10 more clearly illustrating the configuration of the clamp bars and corresponding slots. In particular, it can ibe seen that clamp bar 20 is smoothly contoured on its lower surface.

FIG. 6 is a longitudinal sectional view through the apparatus shown in the preceding figures. It can be seen that button 19 is actually one end of the clamp bar operating shaft 31 which has three ramps 32 formed thereon. These ramps cooperate with corresponding ramps 33 on yclamp bar 17 to raise the bar out of dru'm 10. Wire springs 30 are provided to draw clamp bar 17 back into drum 10. It will be understood that either or both of motors 14 and 16 may be replaced by hand cranks or the like and that various equivalent structures can be provided for those shown in the figures without departing from the concept of the invention. Furthermore, the in- E 4 vention can be satisfactorily employed without stops 24. tive to rotate said drum at a rst rate to wrap a sheet What is claimed is: thereon and at a second rate for utilization of the sheet 1. Sheet to drum clamping means comprising: clamped thereon. (a) a drum journaled for rotation about an axis in a 3. Apparatus according to claim 1 including stop frame; 5 means lmounted With respect to said frarne to prevent (b) a first longitudinal slot in the drum; said Wiper bar from rotating with said drum when out of (c) a clamp bar supported within said drum normally said second slot and to -permit it to rotate with said drum biased to lie Within said first slot and having a when lying in said second slot. plurality of ramp portions thereon; (d) an axially extending cam supported for movement 10 References Clted Within said drum and having ramp portions opera- UNITED STATES PATENTS tively connected to said clamp bar ramp portions 2,049,917 8/1936 Mamma. to move sa1d bar outward from sa1d slot tovrecelve 2 051 511 8/1936 Fich 29 1 L5 first ed e of a sheet of flexible material and to a .dg b 2,513,409 7/1950 Grafstem et a1. 29-118 XR :rnr-fsi/eea toasraiicrliglrldninto `sa1d slot to secure sa1d 15 2,514,974 7 /1950 Schauen (e) a secgond longitudinal slot in the surface of said 2622000 12/1952 Thompson 29-118 XR 2,768,579 10/1956 Pies V 29-118 XR drum adjacent t0 sa1d rst slot; and 0 (f) a Wi b r no u b. d t 1. .,m. .d 2,979,372 4/1/61 Digney.

Per a rma Y me 0 le W1 l Sal v3,203,074 s/1965 Monaghan V- 1o1-415,1XR second slot and removable therefrom supported eX- 20 ternally of said drum t0 provide a Windup tension to FOREIGN PATENTS gesiliiegetcrccl 2100 tsecure a second edge of sa1d sheet 217,534 2/1942 Switzerland.

2. Apparatus according to claim 1 in which there is included drive means connected to said drum and opera- 25' BILLY I' WHHITE Pnmqry Examiner" 

1. SHEET TO DRUM CLAMPING MEANS COMPRISING: (A) A DRUM JOURNALED FOR ROTATION ABOUT AN AXIS IN A FRAME; (B) A FIRST LONGITUDINAL SLOT IN THE DRUM; (C) A CLAMP BAR SUPPORTED WITHIN SAID DRUM NORMALLY BIASED TO LIE WITHIN SAID FIRST SLOT AND HAVING A PLURALITY OF RAMP PORTIONS THEREON; (D) AN AXIALLY EXTENDING CAM SUPPORTED FOR MOVEMENT WITHIN SAID DRUM AND HAVING RAMP PORTIONS OPERATIVELY CONNECTED TO SAID CLAMP BAR RAMP PORTIONS TO MOVE SAID BAR OUTWARD FROM SAID SLOT TO RECEIVE A FIRST EDGE OF A SHEET OF FLEXIBLE MATERIAL AND TO MOVE SAID BAR INWARD INTO SAID SLOT TO SECURE SAID FIRST EDGE TO SAID DRUM; (E) A SECOND LONGITUDINAL SLOT IN THE SURFACE OF SAID DRUM ADJACENT TO SAID FIRST SLOT; AND (F) A WIPER BAR NORMALLY BIASED TO LIE WITHIN SAID SECOND SLOT AND REMOVABLE THEREFROM SUPPORTED EXTERNALLY OF SAID DRUM TO PROVIDE A WINDUP TENSION TO THE SHEET AND TO SECURE A SECOND EDGE OF SAID SHEET IN SAID SECOND SLOT. 